Swivel attachment-plug.



1. LKENNEYI.

SWIVEL ATTACHMENT PLUG.

APPLICATION FILED APR. 25. I9!! Patnted J an. 7,/1919.

2 SHEETS-SHEET l.

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WITNESSES :i es Arar'ENT OFFICE.

JOHNKJ. KENNEY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE BEST ELECTRIC COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATIONQF DELAWARE.

SWIVEL ATTACHMENT-PLUG. l l

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Specification of Letters Patent.

Patented J all. *7., 1919.

To all lwhom t may concern:

Be it known that I, Join' J. KEN Nm', a resident of Pittsburgh, in the county of Allegheny7 and State of Pennsylvania, have invented a new and useful Improvement in Y Swivel Attachment-Plugs, of which the following is a specification.

The invention relates to swivel attachment plugs. y i

It relates more particularly to improvements in the novel form of attachment plug disclosed in the copending application of in a novel manner.

Other objects and advantages of the invention will appear from the following speciiication.

An embodimentof the invent-ion illustrated in the. accompanying drawings, the views of which are as follows Figure lis across sectional view of the parts making up the attachment plug, showmg them in separated relation;

Fig. 2 is a cross section of the assembled attachment plug;

Fig. 3 is a cross section at right angles to Fig. '2; e

F ig. iis a cross section on the line lt-4 of Fig. 2;

Fig. 5 is a cross section ofa modification of the plug shown in the first four figures; and i Fig. 6 is a cross section at right angles to the section shown in Fig. 5.

The attachment plug as a whole includes in general an insulating base l carrying projecting electrical terminals 2 land 3, a screw shell e mounted to rotate about the terminals in electrical engagement with one of them, an insulating spacer 5, and a center contact G connected by a screw 7 to the other terminal for holding the parts together.

The general structure above described is similar to that disclosed in the copending application referred to, but the present structure includes ar number of novel features which will appear from the following description.

The base 1 is made of an)7 suitable insulating material, such as composition fiber. hard rubber, porcelain, or the like. i Itis preferabl)Y made of a material that may be molded to shape, so that the electrical terminals may be molded in position at the time the base made. An axial opening 8 extends through the center of the base to permit conductoi'coids to be passed therethrough.A and in the present construction the top surface of the base has an annular projecting rib 9 which is of suiicient height to act as a guide for the rotatable screw shell, as will hereinafter appear.

The electri lal terminal 2 is carried by the base, and in the construction shown is embedded therein, it being held in position by means of a bushing 10 having` an irregular projecting end buried inl the insulating material of the base. The free end of the terminal projects from the base preferably in line with the periphery of the opening therethrough and the extremeouter end is bent over ]aterally .'as shown in l "igs. l and 2. The terminal carries a binder screw 11,'the head of which engages the outer face of the terminal, and in order to enable a conductor wire to be fastened beneath the binding screw, an openirg l2 is provided through the terminal so that a wire may be threaded from the inside of the terminal through the opening and fixed around the binder screw, as shown in Fig. 1. This enables the wire to be readily attached and at the same time the double-right-angle bend therein causes any withdrawal strains t0 be taken up largelyT by the terminal itself and the strain is relieved from the point. of attachment of the wire.

The terminal 3 is also carried by the base and embedded therein and it projects from the base approximately the same distanceas the terminal 2. It also carries -a binder screw 13 and has an opening 14 for the passage of a conductingwire', the bottom edge of this opening heilig substantially the same distance from the base as the bottom edge'of the opening 12 in terminal 2. The terminal 3 also has a lat-eral projection 15 which is adapted to be engaged by the rotatable screw shell, as Will be hereinafterV explained.

The rotatable screw shell 4 is of the usual type, its lower end being ianged around an insulating washer 1G which forms a gripping surface by means of which the shell may be rotated. The inside diameter of this washer is such that in iianging the shell around itan annular inwardly projecting rib is formed which tits around the annular rib 9 on the base so that the shell is rotatably guided by the coaction of the two ribs. The top of the .1ib in the screw shell forms a shoulder 17 wlnelrengages the projection 15 on the terminal '3 and thus completes an electrical connection between the shell and theterminal.-

The Ilower .end of the shell adjacent the washer 1G 1s surrounded by an insulating ring 18 for preventing any portion of the vshell t being exposed beyond the edge of the lampsocket in .which the plug is inserted.

The insulating spacer 5 is composed of any suitable. insulating material, such vas fiber composition, hard rubber or porcelain.

and its outer' end is preferably rounded lto .facilitate the insertion of the' plug into a. lamp socket. The spacer fits within the screw shell so as to permit the sheli` to be readily rotated and it is provided with two recesses 19 and 20 divided by an insulating wall 21 which, when the spacer is in position,

extends between the terminals 2 and 3 and insulates them from each other. These recesses do not extend to the side exterior of the spacer but are separated therefrom by insulating webs or walls 22 and 23 which extend between the terminals 2 and 3 and the conducting portion of the, rotatable screw shell, thereby completely insulating the terp screwshell but it. projects a sufiicie'nt dis-v tance laterally to preventremoval of the shell as long as the spacer is in position. The shell may be freely rotated, however, with the annular rib thereonrotating in the annular recess formed between the spacer and the base. The side wall 23 has a recess 2+ for the reception ofthe lateral projection .55 15 of terminal 3.

The, parts are held together in the con- /struction shown b v means of a screw 7 passing through the center contact 6 and engaging the bent-over end of the terminal This lscrew electrically connects the terminal with the center contact and at the same time connects the spacer `to the base which in turn holds the screw shellin place. This single means. therefore, forms a Center Contact. und holds the parts together.

The construction described provides a swivel plug in which the terminals are thoroughly insulated from the screw shell and from each other by the. insulating spacer. yet. the terminals are readily accessible. when the spacer and shell are 1"moved The spacer co-acts-with a projection on the base to rigidly position the parts relative to one `another and the rotatable screw shell is guided by an annular projecting rib on the base.- The terminal Qis of exceedingly simple construction, being merely an integral brass strip with its two ends bent at right angles. Nevertheless, this simple structure accomplishes the triple function of a terminal, a strain relief means and ameans for engagement by. the connecting screw for holding the parts together.

ates an annular projectionG on the insulat ing spacer 5. The rotatable screw shell is guided in this construction by the projecting rib on-the spacer, as will be readily under stood by referring` to the drawings. The base and spacer are positioned relative to one another by this structure and are also held in rigid relation.

It is to be understood that the structure .shown is for -purposes of illustration only and that other structures may be devised which come within the spirit and scope ot' the appended claims.

What is claimed is z- 1-. A swivel attachment plug having an insulating base provided with an opening therethrougl. for the passage ol conductor cords, electrical terminals carried b v said base and projecting therefrom, a screw shell mounted to rotate about said terminals in electrical engagement with one ot'. them, the other of said terminals having itsl outer end bent. laterally, an insulating liller. and means passing through an opening in the ller and engaging the bent end of the second terminal to hold the parts together and form a center contact.

Q. A swivel attachment plug comprising an insulating base provided with an opening for the passage of conductor cords. electrical terminals carried b v said base and projecting therefronr` a screw .shell mounted to rotate about said terminals in electrical engagement with one of them. the other ter minal having a bent-over end. an insulating spacer adapted to he positioned in the .screw I shell to insulate the terminals from the shell and from each other` and meanspassing llO with a lateral projection, a rotatable screw shell adapted to rotatably engage the pro jectioii on one f the terminals, an insulating spacer having recesses in which the terminals lie whereby they are insulated from the shell and from each other, and means passing through an opening in the spacer engaging the bent-'over end of the terminal to bend the parts together and forni a center contact.

4. A swivel attachment plug havingl an insulating base provided with an opening for the passage of conductor cords, electrical terminals carried by said base and projecting therefrom, said terminals having means for attaching conductor wires to their outer faces and being provided with openings, the bottom surfaces of which are substantially equally distant from the base, whereby wires of equal length may be attached to the terminals and the terminals themselves relieve the strain from the point of attachment, a screw shell mounted to rotate about said terminals in electrical engagement with one ot them, Y

f: screw shell mounted to rotate about the tei'- an insulating spacer adapted to insulate the terminals and hold the rotatable screw shell in position, and means forming a center contact and passingthrough an opening in the spacer, one of said terminals having a bent-'2 over end arranged to be engaged by said means whereby the parts are held together.

5. Aswivel attachment plug comprising an insulating base having an opening for the 'passage of conducting wires, electrical terminals carried by said base and projecting substantially equal distances therefrom, one of said terminals having a bent-over endand both of the terminals being provided with means forattaching conducting wires to their outerfaces and with openings, the bottom edges of which are substantially equalil distant from the base, whereby wires ot equal length may be attached to the termie nals and the terminals themselves relieve the strain from the point of attachment, a screw shell mounted to rotate about said terminals in electrical engagement with one of them, an insulating spacer having recesses for the reception of the terminals whereby they are" insulated from the 'screw shell and from each other, and a: center contact connected by means of screw passing through an opening in the spacer to the bent-over end of the other terminal whereby the parts are held together.

- 6. -An attachment plug having an insulating base provided with an opening forV tue passage ot conducting wires, integral electrical terminals embedded 1n said baseV and projecting substantially Aequal distances therefrom, one vof said terminals having `a bent-over end and the other having a lateral Y projection struck up therefrom, both of said terminals carrying binder screws by mea-ns of which conductors may be attached .'to their outer faces and both terminals having openings therein, the bottom ledges of which are substantiallyY equal distances from the base whereby wires of equal length may be attached to the terminals and the terminals themselves form strain relief means, a rota:` table screw shellfhaving a shoulder adapted' to rotatably engagethe lateral projection on one of the terminals, an insulating spacer having recesses Yfor receiving the terminals wherebythey are insulated from the screw shell and from each other, said spacerbeingadapted Vto hold the screw shell rotatably in place, and a center contact connected by means of a connecting screw passingthrough an opeiinginthe spacer to the bent-over '90 end of the other terminal whereby the parts are held together and the center contact elecT trically connected t o the other terminal.

7. An attachment plug having-an insulating base provided with an openingfor the 95 passage4 of conducting wires, an annular projecting rib, electrical terminals carried by said base and projecting therefrom, a y

minals in electrical engagement with one of them and to be guided by the annular rib on' the base, an insulating spacer arranged to be positioned within the screw shell to insulate the terminals and hold the screw shell in place, and n'ieans carried by the spacer elec- 105y tricallly connected to the other terminal for holding the parts together and forming a center contact.

8. A swivel attachmentplug having an insulating base provided with an opening for the passage ofV conductor wires and with an annular projecting rib, electrical terminals carried byfsaid base and j nroject-ing therefrom, `said terminals'being arranged to form strain relief means for relieving the strain at the point of attachment of the conductor cords, a screw shell mounted to rotate about the terminals in electrical engagement with one of them and guided by the 'annular rib on the base, an insulating spacerY adapted to be positioned within the screw shell to insu late the terminals and rotatably hold the screw shell in position, and means passing through an opening` in the space-'r and connected to the other terminal to hold the parts together and form a center Contact.

9. A swivel attachment plug comprising an insulating base having an opening for the passage of conduct-ing wires and an annular projecting rib, electrical terminals carried by said bas and projecting' therefrom, one of Said terminals having` a bent-over end and the other having' a lateral projection, and both of rsaid terminals` beingarranged to form strain relief means to relieve the strain at the point ot' attachment ot' the conducting' Wires7 .a screw shell mounted to rotate about.l the terminals: in electrical engagementwith the lat-eral projection on one ot' them and guided by the annular rib on the base, an iusulatlng spacer adapted to be posltloned within the screw shell to rotatably hold the shell in place, said spacer having; recesses tor the reception of thev terminals whereby they are insulated from the screw shell and from each other, and means passing through au opening in the spacer engaging the bento\er end of the other terminal for holding' the, parts together and forming` a center Contact.

In testimon)v whereof, I have hereunto set my hand.

JOHN J. KENNEY. 

